Physical measurements of solar ultraviolet radiation (UVB) and epidemiological data on skin cancer, including malignant melanoma, are collected and analyzed. These studies supply scientific evidence related to the potential consequences of continued ozone depletion and climate change (i.e., global warming), and thus may contribute to policy relative to man-made atmospheric pollutants and international agreements to ban their use, such as the Montreal Protocol. Dose-response estimates and the quantitative effects of atmospheric change on incidence and mortality from skin cancer, including melanoma, are based on these findings. Despite reports of recent stratospheric ozone depletions detected by satellites, our surface-based measurements of solar ultraviolet radiation of 290nm to 330nm wavelengths (UVB) continue to show no increasing trends at urban locations within the United States. The results also agree for rural areas, across continents, and in both hemispheres. Comparison of trends in incidence and mortality rates for malignant skin melanoma and annual and monthly levels of solar ultraviolet UVB indicate that changes in stratospheric ozone depletion do not appear to be responsible for recent worldwide increases in the incidence of melanoma and skin cancer. Age and cohort analyses of skin melanoma mortality rates indicate that males born during the 1950s and females born during the 1930s were at highest risk. Decreasing trends were noted among younger cohorts and age groups under 30. Without additional increases in UVB exposure, we expect to see age-adjusted skin melanoma mortality rates decline early in the 21st century. Incorporating cohort results in estimating the human health effects of ozone depletion is warranted.